Front Horns

A front horn loads the front of the driver, and is meant for reproduction of midrange and highs. The best known examples are the Oris Horn and the Azura Horn. These are normally very large, round horns that reach down to the upper bass region. Well executed designs, like those noted above, allow for greater efficiency, life-like dynamics, and lesser distortion. In particular, the Azura Horn has very little horn coloration.

Unfortunately, the production of large Azura Horns has stopped due to production and shipping problems. Jeffrey Jackson of Experience Music has started importing large wooden horns with the LaCleach expansion (as used in the Azura's), and these should have similar sound

The best drivers for a front loaded horn are the PM4A or the Field Coil. DX4's and PM5A's are often used to good effect as well.

The A55 is the best 5" driver for a front loaded horn, and Martin Seddon (of Azura Horn) or Jeffrey Jackson can both supply horns for this driver.

Use of a proper phase plug in a horn can dramatically affect the response curve. A number of plugs have been used, from the standard bullet and phase equalizer plugs. The wooden "lightbulb" plug is a favorite. bullet plugs which have been lengthened are also often used. It is best to play with these to check their effect.

There are a number of designs which use both front and back horn loading. Shown on the left is the most recent design of the TPI corner horn. Specifically designed for the DX4/EX4 driver, it produces the full audio bandwidth with a single driver. The OPUS 1 is a similar design, and will accept the PM4A. A personal favorite, this is a corner horn design requiring sturdy corners to work best.